Problem: Add.
There are many ways to solve this problem. Let's see two ways we can solve it. Place value table Let's line up the numbers by their decimal places. Ones $.$ Tenths Hundredths ${5}$ $.$ ${7}$ $8$ $9$ $.$ ${1}$ $0$ Now, let's add each place value column. Tens Ones $.$ Tenths Hundredths ${5}$ $.$ ${7}$ $8$ $+$ $9$ $.$ ${1}$ $0$ $\underline{~~~~}$ $\underline{~~~~}$ $\underline{~~~~}$ $\underline{~~~~}$ $1$ $4$ $.$ $8$ $8$ Decomposing the numbers We can group the whole numbers together and the decimals together. $\begin{aligned} &({5}+ {9}) + ({0.78} + {0.10})\\\\ &=14 + {0.88}\\\\ &=14.88 \end{aligned}$ $14.88 = 5.78 + 9.1$